U.S. Pat. No. 3,744,496 describes the use of a carbon-filler innerliner wrapper for smoking articles. More particularly, there is described the use of a carbon-filled cellulosic sheet to reduce total particulate matter yield and organic vapor phase constituents in the mainstream smoke from a smoking article while, at the same time, reducing the visible sidestream smoke.
While generally satisfactory, it has been found, however, that such liners are not entirely satisfactory and have several defects. First, smoking articles containing such innerliners have a very disagreeable sidestream odor. Secondly, the mainstream smoke is deficient in taste. Thirdly, such smoking articles burn with an unattractive flakey ash. Lastly, it has been difficult to control the burning rate of the innerliner. It tends to burn at a rate different from that of conventional smoking article wrapper paper and, because of the use of carbon, the burning tends to undesirably affect the flavor of the smoking article. In some cases, the presence of the carbon also results in sparks upon combustion rendering the resultant smoking article undesirable. There has also been the color problem in that, with innerliners containing high amounts of carbon, they appear nearly black in color, consequently making them visually unsuitable for many smoking products, such as cigarettes, despite the placement thereover of a conventional smoking article wrapper.
Efforts to overcome these problems by the utilization of certain chemicals to control the burning characteristics of the innerliner have not been successful. Included are the materials, such as citrates, phosphates, and nitrate salts, as mentioned in U.S. Pat. No. 3,744,496. The use of such chemicals admixed with the carbon-filled innerliner does not, however, result in any significant improvement in the bitterness, odor, etc., of the smoke or the flaring characteristics of the carbon. The use of flavoring additives has also been unsuccessful.